Are people good at estimating how much they sleep?

By Professor Colin Espie

It depends on how well you sleep! At the poorest end of the spectrum, research literature tells us that people with long term poor sleep tend to overestimate how long it takes them to fall asleep ('Sleep Onset Latency' or SOL), how long they are awake during the night ('Wake Time After Sleep' or WASO), and underestimate their total amount of sleep ('Total Sleep Time' or TST). This has been taken by some to mean that people with long term poor sleep “exaggerate” their problem. Little wonder that many people with sleep problems feel that their complaints are not taken seriously!

However, this discrepancy should not surprise us. People who are normally good sleepers are likely to make very similar 'errors' in estimation on those occasional nights when they sleep poorly. This suggests to me that it is not so much the person with sleep problems who is in some way at fault, rather that the task is actually quite a hard one, and one that good sleepers seldom have to perform. During the night, in the absence of stimulation and activity, time can appear to pass rather slowly (don't you know it!).